PEDRO’S mid-season siesta will end Friday in Atlanta without Willie Randolph having missed a single moment’s sleep for its duration.

“We might be saving some of his bullets,” the manager has said often.

His team’s two-game losing streak going into last night’s game had cut the Mets’ lead only to 11 – and he now has six starters for five spots, regardless. The Mets are so certain of making the playoffs, they have the luxury of conducting open tryouts for their fifth starter spot this next time through the rotation and there is an additional benefit besides.

Not only Martinez now figures to be fresher in October, but, perhaps an extra day will have some benefit for Tom Glavine. After pitching at least seven full innings six times in his first 12 starts, Glavine has made it that far only once in his last eight outings.

In fact, last time out, last week in Cincinnati, he made it into the seventh for only the second time in his last five starts.

Not bad for a 40-year-old, not good for a guy who will pitch Game 2 of the playoffs.

Is Glavine getting tired?

“I think its more of a case that he has been doing this for 19 years and only has 17 inches [of plate] to deal with,” said pitching coach Rick Peterson.

“I don’t think it’s fatigue, it’s a matter of how good big league offenses are.

“The last five years, name a pitcher who has stayed at that level. It’s hard to be that good [every time], and if you are not on your game, somebody else will be. It would be different if you saw 10 to 15 percent of pitchers pitch at that level all the time. Then you would wonder: Where’s the drop-off?” After giving up more than three runs only once in his first 12 starts, Glavine has done so in five of the last eight. Therefore, one doesn’t have to ask; “Where’s the dropoff?” Nevermind he has lost only one of his last 17 starts. That was in Chicago 11 days ago, when he got a quick hook at the first sign of trouble in the sixth, making one wonder if Willie isn’t just saving Pedro’s bullets but now keeping inventory on Glavine’s too.

Perhaps a six-man rotation should keep turning past the Mets upcoming visits to Atlanta and Florida, through a second or third time.

“There would always be a benefit to the freshness,” said Peterson. “On the flip side of the coin, pitchers are creatures of habit.

“In a five-man rotation, they get in a routine that’s like clockwork. That’s the danger of going with six. The plus side, especially at this point of the season, is what that might add for you on the back end.” Randolph has no plan to continue this indefinitely.

Martinez no longer needs it and Glavine, one of those ultimate creatures of habit, will insist he doesn’t, either. To help prove that, he needed to follow up his performance the last time out in Cincinnati (two runs on nine hits in 6 1/3 innings) with another good one last night.

Maybe Mets fans just need something to worry about, even 11 games up. But if Glavine comes into the playoffs pitching like a back-endofthe-rotation kind of pitcher, this will be a team that could lose in any round. The Mets need for the Orlando Hernandez, who has shown a lot of age even if it can’t be verified on a birth certificate, to be their fourth playoff starter, not the third. That means they still could use a trade for a more experienced hand than John Maine and Mike Pelfrey and a better one than Steve Trachsel.

But the Mets need a better Glavine, too, because what statistically is the best bullpen in the National League won’t last deep into October if he can’t last past the fifth inning.